pplpod

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Paris syndrome is a rare, acute form of culture shock documented mainly among Japanese visitors to the French capital. Its psychiatric symptoms include delusional states, depersonalization, derealization and a conviction of being persecuted by locals, and its physical ones include dizziness, sweating, vomiting and a racing heart. A 2004 paper by Viala and colleagues in the French journal Nervure named four causes: the language barrier, friction between harmony focused Japanese etiquette and informal Parisian manners, exhaustion from long flights and jet lag, and the gap between an idealized Paris and a crowded, littered, pickpocket prone city. A 2016 paper split sufferers into those with prior psychiatric history and those with none who develop a delayed stress reaction.

The clash is old. Sir Thomas Browne warned in 1656 that weak constitutions should avoid cities like Paris and Rome, and in 1732 Jean-Jacques Rousseau expected marble and gold palaces but found stinking streets, black houses and beggars, an aversion he said never left him. Japanese psychiatrist Hiroaki Ota named the syndrome in the 1980s while treating patients at Sainte-Anne Hospital and published a book in 1991. In 2006 outlets including the BBC reported a Japanese embassy emergency hotline and repatriation flights, which the embassy denied. The real figure is about three to five hospitalizations a year among roughly 1.1 million Japanese visitors.

• How a surge of arrival excitement gets reinterpreted as panic when reality fails the brain's predictions
• Mario Renoux of the Franco-Japanese Medical Association blaming advertising for a city of ghosts
• Chinese tourists reported leaving Paris in tears by 2014
• A 2012 Paris tourism office survey citing safety and cleanliness, and police translating their website into Chinese
• Graziella Magherini's Stendhal syndrome in Florence as the mirror image, triggered by overwhelming beauty

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

A cat whose left foreleg was amputated months earlier still tries to scoop litter with the missing paw, and between 50 and 80 percent of human amputees likewise feel a limb that is gone. This episode separates phantom limb syndrome, the often painless sense of presence, from phantom limb pain, and describes kinetic, kinesthetic and exteroceptive sensations, including phantom itches and telescoping, where the limb seems to shrink toward the stump. Phantoms also follow tooth extractions, eye removal, mastectomies and gender affirming surgeries, because the sensation lives in the brain's primary somatosensory cortex. Ambroise Paré documented soldiers' phantom pain on 16th century battlefields, and in 1872 Silas Weir Mitchell named the condition and called it a sensory ghost.

For decades doctors blamed irritated nerve endings, called neuromas, until Ronald Melzack noted in the late 1980s that people born without limbs also feel phantoms and proposed a brain wide neuromatrix. In 1991 Tim Pons and colleagues at the NIH showed that monkey brain maps redraw their borders, and V.S. Ramachandran found that stroking an amputee's cheek produced feeling in the missing thumb. Researchers such as Tamar Makin at Oxford also study signals from the stump, and central sensitization in the spinal cord adds to the pain. Drugs work poorly, so treatment has moved from Ramachandran's mirror box to virtual reality.

• The theory that a final clench command, never answered by a real hand, gets stuck in a painful loop
• A 2025 scoping review finding mirror therapy results highly inconsistent across patients
• The four phases of Targeted Brain Rehabilitation, from left and right recognition to guided motor execution
• A study of 36 upper limb amputees in which 90 percent reported changes in pain after one session
• A large trial with pain drops of 64 percent for motor execution and 68 percent for imagery, and the PIVOT program starting VR right after surgery

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

The polygraph is a 2 billion dollar American industry running about 2.5 million tests a year, yet it detects no lie. Its rubber tubes, blood pressure cuff and finger plates record breathing, cardiovascular activity and skin conductance, the signs of fight or flight arousal. Examiners prime subjects with a rigged stim test card trick, then compare reactions to irrelevant, control and relevant questions, while Japan uses the concealed information test, which looks for involuntary recognition of withheld crime details. The device began with William Moulton Marston at Harvard around 1915, inspired by his wife Elizabeth Holloway Marston's remark that her blood pressure rose when she was angry. Marston later appeared in 1938 Gillette razor ads and created Wonder Woman and her Lasso of Truth. John Augustus Larson in Berkeley added breathing in 1921, and Leonard Keeler added skin response, made it portable and sold it to the FBI.

A 2003 National Academy of Sciences review of about 80 studies found the research weak and warned against screening employees. In the 1998 case United States v. Scheffer the Supreme Court upheld a ban on polygraph evidence, likening its accuracy to a coin toss, and most of Europe, Canada and Israel reject it in criminal trials. Agencies keep it because frightened subjects confess. CIA officer Aldrich Ames passed twice while spying for the Soviets, Green River Killer Gary Ridgway passed in 1984, and Kansas widower Bill Wegerle failed two tests after his wife's 1986 murder, living under suspicion until DNA in 2005 identified BTK killer Dennis Rader.

• How the stim test convinces subjects the machine is infallible before the real questions begin
• Specific countermeasures like biting the tongue or pressing a tack in a shoe during control questions
• The KGB's simple advice to Ames: sleep well, be friendly and stay relaxed
• A 2013 federal crackdown involving about 30 agencies against people teaching how to beat the test
• The next generation of truth machines built on fMRI scans and AI analysis of micro-expressions

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Jerusalem syndrome is an umbrella term for religiously themed delusions and psychotic episodes triggered by a visit to the city, and it crosses Christian, Jewish and Muslim lines and sometimes affects secular visitors. The pattern long predates jet lag. The 15th century itinerary of Dominican monk Felix Fabri describes pilgrims wandering the hills reenacting biblical suffering, and English mystic Margery Kempe, around 1413, wept so loudly at the holy sites that she alienated her fellow travelers. Nineteenth century writers called it Jerusalem fever and dismissed it as hysteria until psychiatrist Heinz Herman began documenting cases as clinical events in the 1930s. The syndrome still appears in neither the DSM nor the International Classification of Diseases.

In 2000 Bar-El and colleagues published three types in the British Journal of Psychiatry: people with prior psychotic illness who travel because of their delusions, people with intense idiosyncratic beliefs short of psychosis, and previously healthy tourists who break suddenly and recover after going home. Kalian and Witztum attacked that third type, noting there were no records proving those patients had been well. Kfar Shaul Mental Health Center saw about 100 affected tourists a year from 1980 to 1993, roughly 40 admitted, against about 3.5 million annual visitors. Bar-El predicted a millennium epidemic, hospitals set up triage, and it never came. The city, the critics argue, supplies the imagery but not the illness.

• Fabri's pilgrims searching for nonexistent relics in the 15th century
• Type three patients bathing compulsively, cutting hair and nails, and preaching in togas made from hotel sheets
• Why 40 hospitalizations out of 3.5 million visitors matches ordinary background rates of psychiatric crisis
• Pop culture uses from a 2010 Simpsons episode and The X-Files to Black Box, a Joshua Sobol play and Neil Gaiman's Trigger Warning
• A 2016 Metropolitan Museum of Art catalog that opened with the syndrome as a metaphor for the weight of history

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

In early 1936, an 86 year old Ivan Pavlov lay dying of double pneumonia and asked a student to sit by the bed and record his final physiological sensations. This episode traces how the eldest of 10 children of a village Russian Orthodox priest in Ryazan ended up there. A severe fall from a wall at age seven kept him out of school until 11, and he later left a theological seminary after reading Dmitri Pisarev and Ivan Sechenov, who argued that all brain functions were reflexes. In St. Petersburg he and his wife Serafima lived in deep poverty, staying with friends, and their first son died in early childhood. Pavlov rejected acute vivisection experiments and invented the Pavlov pouch, an isolated section of stomach with its vagus nerve endings intact, which earned him the 1904 Nobel Prize for the physiology of digestion, not for conditioning.

Long term dogs in his lab began salivating at a technician's footsteps, which Pavlov called psychic secretion and turned into the study of conditional reflexes. In 1994 A. Charles Catania's review of the original Russian texts found metronomes, harmoniums, whistles, tuning forks, rotating disks and mild shocks, but no clear role for the famous bell. After the revolution H.G. Wells found Pavlov growing potatoes and carrots in his lab courtyard, Lenin granted him double rations and lavish funding, and Pavlov still wrote to Stalin and Molotov protesting persecution of intellectuals. His Nobel fame shielded him. Late in life he studied how stressed dogs shut down, mapping four nervous system types onto the temperaments of Hippocrates and Galen.

• How the Pavlov pouch collected pure gastric juice from healthy dogs that lived in his kennels for years
• Why Pavlov wanted precise stimuli like metronomes rather than a handbell whose volume and pitch vary
• His 1923 lecture saying he would not sacrifice a frog's hind leg to the communist social experiment
• Transmarginal inhibition, the protective shutdown he triggered with flooding kennels and overwhelming noise
• His influence on John B. Watson, B.F. Skinner, systematic desensitization and Aldous Huxley's Brave New World

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Hiccups have a folk reputation as a sign that someone is talking about you, a belief found in Slavic, Turkish and Luo traditions, but the medical reality is mechanical. The reflex, called singultus from the Latin for a sob, is a two part event: a sudden involuntary spasm of the diaphragm pulls air in, and about 35 milliseconds later the glottis snaps shut, and that collision makes the hic sound. Everyday triggers include eating fast, spicy food, carbonated drinks and swallowing air, but the same reflex arc can be set off by kidney failure, meningitis, multiple sclerosis, a heart attack, and in one documented case a Plasmodium vivax malaria infection. The common thread is irritation somewhere along the sprawling vagus and phrenic nerves.

The episode weighs two evolutionary explanations. The burping reflex hypothesis says hiccups evolved in suckling mammals to pull swallowed air out of an infant's stomach and make room for milk. The phylogenetic hypothesis traces the reflex to tadpoles, which gulp water across their gills and then close the glottis, and notes that human fetuses develop hiccup pathways before breathing pathways. Medicine classifies hiccups as a bout up to 48 hours, persistent up to a month, and intractable beyond that, most often in adult men and usually on the left side of the diaphragm. British singer Christopher Sands hiccuped for 27 months from February 2007 until surgery in 2009 removed the brain stem tumor pressing on his medulla.

• Charles Osborne began hiccuping in 1922 after slipping while slaughtering a hog and continued until 1990, an estimated 430 million hiccups
• Premature infants in neonatal intensive care spend about 2.5 percent of their time hiccuping
• Raised carbon dioxide and drugs acting on GABA-B receptors stop both tadpole gulping and human hiccups
• A Journal of Internal Medicine case report of intractable hiccups ended by digital rectal massage, alongside implanted vagus nerve stimulators
• The SSMI breathing technique and the FIST device, sold as the HiccAway straw, which over 90 percent of study participants rated above home remedies

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Horripilation, the pilomotor reflex better known as goosebumps, begins when the sympathetic nervous system releases norepinephrine onto tiny erector pili muscles that anchor the skin's basement membrane to hair follicles. Recent anatomy shows one muscle often controls a cluster of follicles, and its contraction squeezes sebaceous glands to push oil to the surface. The follicle's deep bulb gives the muscle a firm anchor to pull against. In furred mammals the reflex traps insulating air and makes animals look bigger, from porcupines and cats to sea otters facing sharks. In nearly hairless humans it is a vestigial reflex.

A bug on the arm triggers local goosebumps, while cold or strong emotion sets off a whole body response, though sensor studies found reported music chills rarely involve actual muscle contraction. Goosebumps can signal temporal lobe epilepsy or autonomic hyperreflexia, and opiate withdrawal produces so much piloerection that skin resembles a plucked turkey, the origin of going cold turkey. In 1500s London, Winchester geese meant sex workers in Southwark licensed by the Bishop of Winchester, and goose bumps took on a whispered link to syphilis.

• The hair follicle has four parts: bulb, suprabulbar area, isthmus, and infundibulum
• Yohimbine, a tree bark alkaloid, triggers goosebumps by releasing norepinephrine
• Several languages name the reflex after chickens or hens, Hebrew after a duck, and Russian and Ukrainian after crawling ants
• Voluntarily generated piloerection is an innate ability, usually discovered by accident
• People who can raise goosebumps at will tend to score high in openness to experience

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

A bone marrow transplant can change a patient's blood type, because the donor's stem cells take over red cell production. This episode explains why that is possible: a blood type is the set of antigens on red blood cells, policed by antibodies in the plasma, and the International Society of Blood Transfusion recognizes 49 blood group systems, including Kell, Duffy, Kidd, and Lewis. Many of those variants trace to disease. One malaria parasite uses the Duffy antigen to enter red cells, so Duffy negative blood became common in people of African descent, and type O cells resist the sticky rosetting caused by malaria infection.

Karl Landsteiner first noted serum clumping in a short footnote in 1900 and defined the A, B, and O groups in 1901. Then Jan Janský in 1907 and William Moss in 1910 created Roman numeral systems that ran in opposite directions, causing confusion in hospitals until the League of Nations standardized the letters in 1928. The episode covers acute hemolytic reactions, hemolytic disease of the newborn and Rho(D) immune globulin, and Japan's and South Korea's blood type personality beliefs.

• Frontline Waffen-SS troops had their blood group tattooed under the left arm
• Rh negative mothers make anti-D antibodies only after exposure to Rh positive blood
• Type O is the universal red cell donor, but type AB plasma is the universal plasma donor
• People with the Bombay phenotype lack the H antigen and react even to O negative blood
• Blood type emojis were added to Unicode because of the personality trend, not for medicine

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Charles Darwin's 1871 book The Descent of Man described rudimentary structures like body hair, wisdom teeth, and the tailbone. In 1893 anatomist Robert Wiedersheim went much further and listed 86 human organs as wholly or partly functionless, including the pineal gland, thymus, and pituitary, whose roles were not yet understood. That outlook fed the focal infection theory, and a 1916 journal reported removing an appendix to cure facial nerve pain. This episode tours the body's genuine leftovers and the ones that turned out to matter, starting with the appendix as a safe house for gut bacteria that has evolved independently at least 32 times in mammals.

Softer cooked food shrank human jaws while genes such as PAX9 kept the tooth count, leading to impacted wisdom teeth. Every embryo grows a tail around days 31 to 35 before cells remove it. Thin ear muscles once swiveled the ear, the neck's platysma is a remnant of the skin muscle horses use to flick off flies, goosebumps are left from fur, and newborns can grip hard enough to hang their own weight. The episode ends with the broken vitamin C gene GULO and hiccups traced to the way tadpoles gulp water past their gills.

• Wisdom tooth agenesis is almost zero among Tasmanian Aboriginal people and nearly 100 percent in some Indigenous Mexican populations
• The embryonic tail reaches about a sixth of the embryo's length, and rare babies are born with 12 centimeter pseudo tails
• A 1932 study found over 37 percent of infants could support their body weight hanging from a rod
• The vomeronasal organ appears in over 90 percent of adults but has no working neurons, and its TRPC2 gene is a pseudogene
• Premature infants spend about 2.5 percent of their time hiccuping

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

Charles Darwin corresponded with missionaries and doctors worldwide to learn whether all peoples blush, and called it the most peculiar and most human of all expressions. This episode separates blushing, which needs an emotional trigger, from flushing caused by heat, exercise, fever, or alcohol. Blushing occurs in the blush region of the cheeks, forehead, ears, neck, and upper chest, where research by Wilkin found denser, wider, shallower capillaries. A 1982 study by Mellander and colleagues showed that facial veins hold a constant basal tone and carry beta adrenoceptors that release that tension and let blood rush in.

In 1997 Drummond fitted undergraduates with laser Doppler flow meters on their foreheads. Blocking alpha receptors had no effect on blushing, and beta blockers delivered through the skin reduced it but did not stop it, pointing to backup mechanisms. Psychologist Ray Crozier calls the blush an involuntary apology that cannot be faked, while Salzen proposed in 2010 that it is thwarted fight or flight energy. Imaging links blushing to the cerebellum and the left paracentral lobe.

• Flushing is about physical heat, while blushing responds to social situations
• Facial veins act like coiled springs, held tight until a social trigger releases them
• For people with social anxiety, fear of blushing can itself trigger more blushing
• Idiopathic craniofacial erythema causes intense blushing with almost no provocation
• Endoscopic thoracic sympathectomy cuts or clamps sympathetic nerves in the chest to block the signal